CVE-2026-19490: Citrix NetScaler

What is CVE-2026-19490?

Vulnerability in NetScaler ADC and NetScaler Gateway. This issue affects ADC: from 14.1 through 73.32 and from 13.1 through 63.21; Gateway: from 14.1 through 73.32 and from 13.1 through 63.21.

CVSS9.8 NVD 3.1

SeverityCRITICAL

Exploitation In the wild In CISA KEV

EPSS23% · P98

Triage statusActive Exploit

ActionPatch immediately

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWECWE-288

NVD published2026-08-19

NVD last modified2026-10-07

Timeline

2026-08-19Published to the U.S. National Vulnerability Database (NVD)
2026-09-05First covered in a defend.network daily briefing
2026-09-09Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2026-09-12CISA federal remediation deadline (BOD 22-01)
2026-10-07NVD record last updated

CISA Known Exploited Vulnerability

Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability

Added to KEV2026-09-09

Federal patch deadline2026-09-12

Known ransomware useUnknown

Affected product

Citrix NetScaler

NVD also lists CPE entries for: Citrix Netscaler Application Delivery Controller, Citrix Netscaler Gateway

Remediation Steps

Apply the vendor security update for Citrix NetScaler as a priority.
Restrict network exposure of the affected service to trusted sources until patched.
Review logs and detections for indicators of exploitation.
Confirm fixed versions against the official vendor advisory before deploying.

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 1 of October 2026 (October 5 – 11)
Vulnerability Priority Report – Week 4 of September 2026 (September 28 – October 4)
Vulnerability Priority Report – Week 3 of September 2026 (September 21 – 27)
Vulnerability Priority Report – Week 2 of September 2026 (September 14 – 20)
Vulnerability Priority Report – Week 1 of September 2026 (September 7 – 13)
Android malware surge; AI-powered PaperCut campaign hits 395+ orgs (2026-09-11)
VMware, Magento, JetBrains hit by active exploits; credentials compromised (2026-09-06)
PostgreSQL, WordPress plugins, Citrix NetScaler under active attack; Unicode phishing surge (2026-09-05)

Browse all tracked CVEs in the defend.network CVE database →

🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.